Knee
Anatomy
The knee is a hinge type of joint where the lower end of the the thigh bone (femur) articulates with the top of the shin bone (tibia). The ends of the these bones are covered by articular cartilage to allow smooth movements.
These bones are supported by number of muscles around them which provide stability in addition to the ligaments and menisci (sports cartilage). Joint fluid (synovial) is produced which lubricates the joint and permits a wide range of pain free movement.
Muscles surround the knee joint facilitate movement around the knee and it is essential that these muscle groups are adequately rehabilitated after any knee surgery in order to restore function.
Function
The knee is a very versatile and stable joint which supports the body in both static (standing) and dynamic (moving) postures. Huge loads are transmitted through the knees which can be as much as three times the body weight.
What is a Total Knee Replacement
If you have arthritis of the knee, the first strategy is start conservative treatment.
These treatments may include:
- Weight loss
- Physiotherapy to strengthen the muscles around the knee
- Painkillers
- Cortisone Injections
- Walking aids such as a stick or a frame
If after these you as a patient are not satisfied, then surgical procedures may be considered.
A total knee replacement involves replacing the whole of the knee joint. This may or may not include replacing the undersurface of the knee cap (patella).
The Operation
You will either have a general anaesthetic, or a spinal anaesthetic.
The operation will last between 1 and 2 hours.
A tourniquet is placed around the thigh prior to the operation to minimise blood loss during the procedure
A cut is made over the front of your knee. The diseased bone is cut out using specialised cutting blocks and then the implant is put in its place. These are tested to ensure they work well.
The wound is then closed and glued together. This reduces the need to use clips which can be uncomfortable to remove.
After the operation
Immediately after the operation, you will be transferred to the recovery room and then the ward once you are stable.
You will have:
- A drip inserted into a vein in your arm that supplies fluids or blood.
- A bulky dressing around the knee.
- A drain to reduce swelling around the operation site which is removed the following day.
- Blood tests and X-rays will be taken in the early post-operative period.
Pain relief
Good pain relief is important and it is better to try and prevent pain before it gets too bad.
Pain relief can be increased, given more often, or given in different combinations. Please ask help from the nurses on the ward if you are in any discomfort.
Rehabilitation programme
A physiotherapist will visit you on the day of your surgery and begin teaching you how to use your new knee. You may be fitted with a continuous passive motion (CPM) machine that will slowly and smoothly straighten and bend your knee.
It is extremely important that you adhere to this exercise programme and take the necessary precautions with your new knee.
Patients can usually return to work after 6 weeks although this period may be longer for heavy manual work. By three months, most patients can participate in low impact sports such as golf, bowls, cycling and swimming.
General home advice
It is expected to have some pain but not the same sort of pain that was there before the surgery. This can last up to few weeks but not generally. It is often helpful to take painkillers, if needed. Swelling and bruising may also take up to 6-8 weeks to disappear – very rarely they continue up to 6 months.
The wound is normally checked at 2 weeks after the surgery. I use glue instead of clips so there is no need for anything to be removed. Also I believe it gives a more cosmetic scar. At this point providing the wound is fine then you can take a shower or bath with the wound covered in a waterproof dressing. It is important to comply with the physiotherapy advice which will improve your overall outcome after the surgery.
Possible Complications
This is a very successful operation, but there are some risks associated with any type of surgery.
Complications can occur as a result of the anaesthetic, the knee replacement itself or as a general result of having a major surgery:
Complications specific to knee replacement
Infection
The risk of infection after knee replacement is about 1%. The majority of infections can be treated with antibiotics. Seldom further surgery is required to wash out the joint and on occasion the knee replacement needs removal.
Blood Clots
These can form in the veins (Deep vein thrombosis) which can travel to the lungs and cause a pulmonary embolism (PE). This can be life threatening but is of low frequency. We minimize the risks of this by encouraging early mobilization, elastic stockings, foot pumps and taking blood thinning medications.
Bleeding
A tourniquet is used to minimize blood loss during surgery. Moreover, meticulous soft tissue dissection is performed to reduce excessive blood loss. However, occasionally a blood transfusion may be necessary.
Medical Complications
These can include a heart attack, stroke, chest infection and bowel obstruction. Very rarely there is a risk of death
Nerve Damage
There are small skin nerves around the incision site which invariably are damaged causing a small patch of numbness around the knee. On occasion the major nerves can be stretched or damaged. The most common result of this is a foot drop. The majority of these recover with time.
Ligament Damage
There is a small possibility of damage to the patellar tendon and collateral ligaments of the knee. This is identified and dealt with at the time of surgery. This may result in wearing a knee brace to allow the ligament to heal.
Wear
The majority of knee replacements will last for 10-15 years. Once it does become loose then it may need to be replaced.
Stiffness
Some patients have a propensity to form excessive scar tissue after total knee replacement. This can stiffen the knee and reduce the bend they can achieve. If physiotherapy does not improve the bend then a manipulation under anaesthetic is required to break down the scar tissue and improve the knee bend. If this does not give adequate improvement then I can re-operate on the knee and cut out the scar tissue to improve the movement of the knee.
What is a Unicompartmental Knee Replacement (UKR)?
If you have osteoarthritis of the knee you may be having conservative treatment to improve your symptoms.
These treatments may include:
- Weight loss
- Physiotherapy to strengthen the muscles around the knee
- Painkillers
- Cortisone Injections
- Walking aids such as a stick or frame
If after these you as a patient are not satisfied, then surgical procedures may be considered.
A unicompartmental knee replacement involves replacing only the most damaged part of the knee
A UKR may be considered if you
- Have arthritis confined to one part of the knee
- Have an intact Anterior Cruciate Ligament (ACL)
- Have no significant inflammation
- Do not have significant damage to the other compartments
- Do not have marked stiffness around the knee
What are the benefits compared to a full knee replacement (Total Knee Replacement)?
- faster rehabilitation and quicker recovery
- less blood loss
- less morbidity
- smaller incision
- less post-operative pain leading to shorter hospital stays
The Operation
You will either have a general anaesthetic, or a spinal anaesthetic.
The operation will last between 1 and 2 hours.
A tourniquet is placed around the thigh prior to the operation to minimize blood loss during the procedure
A small cut, usually over the front of your knee is made.
The diseased bone is cut out and the implant is put in its place
These are tested to ensure they work well
The wound is then closed and glued together. This reduces the need to use clips which can be uncomfortable to remove.
After the operation
Immediately after the operation you will be transferred to the recovery room and then the ward once you are stable.
You will have:
A drip inserted into a vein in your arm that supplies fluids or blood.
A bulky dressing around the knee
- A drain to reduce swelling around the operation site which is removed the following day
- Blood tests and X-rays will be taken in the early post-operative period to ensure that blood levels have not substantially changed and that the knee replacement is in a satisfactory position.
Pain relief
Good pain relief is important and it is better to try and prevent pain before it gets too bad.
Pain relief can be increased, given more often, or given in different combinations. Please ask help from the nurses on the ward if you are in any discomfort.
Rehabilitation Programme
A physiotherapist will visit you on the day of your surgery and begin teaching you how to use your new knee. You may be fitted with a continuous passive motion (CPM) machine that will slowly and smoothly straighten and bend your knee.
It is extremely important that you adhere to this exercise programme and take the necessary precautions with your new knee.
Patients can usually return to work after 6 weeks although this period may be longer for heavy manual work. By three months most patients can participate in low impact sports such as golf, bowls, cycling and swimming.
General home advice
You can expect some pain but not the same sort of pain as you had before the operation. The time it lasts will vary from a few days, to several weeks; everyone is different. It is important to take your painkillers as advised. Swelling and bruising may take up to 6-8 weeks to disappear; for some it can last up to 6 months.
The wound will normally be checked 2 weeks after the operation in Mr Shahid’s clinic. I use glue instead of clips so there is no need for anything to be removed. Also I believe it gives a more cosmetic scar. At this point providing the wound is fine then you can take a shower or bath with the wound covered in a waterproof dressing. It is important to comply with the physiotherapy advice which will improve your overall outcome after the surgery.
Possible Complications
This is a very successful operation, but there are some risks associated with any type of surgery.
Complications can occur as a result of the anaesthetic, the knee replacement itself or as a general result of having major surgery:
Complications specific to knee
Infection
The risk of infection after knee replacement is about 1%. The majority of infections can be treated with antibiotics. Seldom further surgery is required to wash out the joint and on occasion the knee replacement needs removal.
Blood Clots
These can form in the veins (Deep vein thrombosis) which can travel to the lungs and cause a pulmonary embolism (PE). This can be life threatening but is of low frequency. We minimize the risks of this by encouraging early mobilization, elastic stockings, foot pumps and taking blood thinning medications.
Stiffness
Some patients have a propensity to form excessive scar tissue after total knee replacement. This can stiffen the knee and reduce the bend they can achieve. If physiotherapy does not improve the bend then a manipulation under anaesthetic is required to break down the scar tissue and improve the knee bend. If this does not give adequate improvement then I can re-operate on the knee and cut out the scar tissue to improve the movement of the knee.
Wear
The majority of knee replacements will last for 10-15 years. Once it does become loose then it may need to be replaced.
Ligament damage
There is a small possibility of damage to the patellar tendon and collateral ligaments of the knee. This is identified and dealt with at the time of surgery. This may result in wearing a knee brace to allow the ligament to heal.
Nerve Damage
There are small skin nerves around the incision site which invariably are damaged causing a small patch of numbness around the knee. On occasion the major nerves can be stretched or damaged. The most common result of this is a foot drop. The majority of these recover with time.
Bleeding
A tourniquet is used to minimize blood loss during surgery. Moreover, meticulous soft tissue dissection is performed to reduce excessive blood loss. However, occasionally a blood transfusion may be necessary.
Medical complications
These can include a heart attack, stroke, chest infection and bowel obstruction. Very rarely there is a risk of death
WHAT IS AN ARTHROSCOPY?
Arthroscopy (keyhole surgery) allows the surgeon to view the inside of your joint, providing a more accurate way to diagnose and treat certain conditions.
A small camera is inserted into the knee and the images are projected onto a television screen.
Specialist instruments are introduced into the joint through small incisions.
Why will I need an Arthroscopy?
To investigate symptoms such as pain, swelling, or instability of a joint.
It may highlight damage to cartilage or ligaments within a joint, fragments of bone or cartilage which have broken off (‘loose bodies’), or signs of arthritis.
Injuries to the menisci which are 2 semicircular structures that act as shock absorbers within the knee joint. They can be injured by twisting activities resulting in pain, instability, clicking and locking of the knee. If you have a tear in the meniscus the torn section is ‘trimmed’ back to healthy stable meniscus. Sometimes it may be possible to repair the torn cartilage.
Injuries to the articular cartilage, which lines the surface of the knee, can be addressed by procedures such as microfracture
Loose fragments of bone or articular cartilage can be removed from the joint.
Biopsies can be performed and sent for further investigations as to the cause.
Scar tissue can restrict the movement of the knee and an arthroscopy can be used to release this.
The kneecap (patella) can be a source of pain in the knee. The arthroscope allows inspection of the patella under surface. If there is any loose articular cartilage this can be shaved.
Before your arthroscopy
Prior to your arthroscopy, your knee may be painful and swollen. Even though it is a relatively minor procedure, it is important that you understand what is involved in an arthroscopy and what you will be required to do immediately after the procedure.
We will discuss issues such as:
- Returning to work
- Using crutches
- Driving
- Alternative ways to remain active without damaging the surgery
- Anticipated length of rehabilitation
You may be given an exercise rehabilitation programme which should begin before surgery so that your knee is in the best possible condition on the day of surgery.
The operation
The procedure can last between 30 minuets to an hour depending upon what procedures are required.
It is usually performed under a general anaesthetic as a day case. However, there may be occasions whereby the patient requires overnight stay.
After he anaesthetic a tourniquet (a form of tight bandage) is placed around your thigh prior to the procedure. This is minimises bleeding within the knee during the arthroscopy allowing the surgeon to get the best view inside the knee. The tourniquet rarely causes a problem, but may leave you with a “tight” feeling around the thigh for a day or two.
Two to three small incisions (1cm) are made at the front of the knee to allow insertion of the arthroscope and instruments.
Normal Saline fluid is passed through the knee which helps inflate the knee and makes visualisation of the knee structures easier.
Local anaesthetic is injected into the knee to minimise discomfort after surgery.
Stitches are required to close the wounds; these will be removed after 14 days when you see me in the outpatients department. A bandage is applied after surgery which should be removed ithe following morning after surgery.
What happens after the procedure?
We will give you instructions on how much weigh to put through your leg, and when to start physiotherapy. Your GP and physiotherapist will be sent a summary of the operation.
You will normally be seen in the out-patient clinic 2 weeks after surgery. At this appointment, the bandages will be removed. The operation that was performed will be explained to you again as well as any follow up treatments that may be required.
Possible complications
All operations have a small risk of complications.
In most cases the procedure is done without any problems. Complications occur in less than 1 in 100 cases and can include:
Blood clots – Any surgery of the legs can increases the risk of blood clots in the veins. The use of HRT and oral contraceptive pills may increase the risk of thrombosis and may need to be stopped before surgery.
Infection –within or around the joint.
Bleeding – This can seldom occur and if severe may require a return to theatre for removal of the blood.
Failure to improve – On occasion this procedure may not cure your symptoms. If this is the case other options of treatment will be discussed with you.
Accidental damage – to structures inside or near to the joint. This is extremely rare but there are occasionally symptoms from the small nerves around the knee.
KNEE ARTHROSCOPY PROTOCOL
Dressing instructions:
Keep wounds clean, dry, and covered at all times until Outpatient Review
First day after surgery:
Remove outer wool and crepe bandages, leaving sticky plasters in place. These dressings allow showering, but not bathing. They should not be submerged.
The wounds should be covered with Tegaderm dressings for at least 14 days. They can be removed if they start to peel off, and be replaced. Do not pick at the stitches underneath the dressing.
If the dressing is peeling and you are not keen to take it off, then it may be best to reinforce it with a further dressing on top, and try to keep it as dry as possible.
Post-op care of your knee:
Ice and elevation help reduce swelling and inflammation. Always cover the ice with either a towel or pillowcase. Ideally you should only ice for 20 minutes at a time every 2 hours.
It is advisable to take the painkiilers prescribed for at least five days even if you are not in pain. These can help prevent pain and reduce inflammation around the knee.
Please contact Mr Shahid’s office or the hospital if you have any further queries.
